Why be in such a hurry to melt the carb ice? Do you prefer the engine to ingest BIG LUMPS of ICE, instead of smaller amounts.
Each of the local training establishments that I have knowledge of, all say that there are three times when you should apply carb heat... 1. If you think carb icing is likely. 2. Any time the engine is run below 2000rpm. and 3. As the C in the downwind pre-landing BUMFFPITCHH checks.